Slit-forming device and method of producing the same



W723, 1933; Y V J) ENGL 1,910,598

sm-r rommm DEVICE Anb uamon OF PRODUCING THE: slum Filed June 19, 1930 1 INVENTOfi ebsefl flzgl BY ATTORNEYS Patented May 23, 1932i I UNITED STATES PATENr OFFICE J'OSEF ENGL, OF BERLIN -GRUNEWALD, GERMANY, ASSIGNOR TO ENGL PRODUCTS CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK SLIT-FORMING DEVICE AND METHOD or raonucme THE slum Application filed Iune 19, 1930, Serial No. 462,200, and in- Germany February 11, 1929.

My invention relates to a member or device which forms or defines a slitor passage to be traversed by a light beam utilizable in various optical systems, such for example, as for recording sound waves on a film or the like or for reproducing sound from such a and which is operative in a highly efilcient manner for the intended purposes. s

Various other objects, advantages and characteristics of my invention will-become apparent from the following detailed description taken in connection with the accompanying drawing. My invention resides in the article, device, arrangement, method, and features of construction of the character hereinafter described and claimed.

For an understanding of my invention and for an illustration of some of the many forms thereof reference is to be had tothe accompanying drawing, in which:

Figure 1 is an end view-of a slit-forming device as constructed in accordance with my the deinvention Fig. 2 is a side elevational view of gice shown in Fig. 1;

Fig. 3 is a plan view of the device shown in Fig. 1;

Fig. 4 is an end view of another form of slit-forming device as constructed in accordance with my' invention;

1 Fig. 5 is a side elevational View of the device shown in Fig. 4; and

Fig. 6 is a plan view of the device shown in Fig. 5.

' In general, my invention relates to, slitforming devices wherein the slit is traversed by a light beam which cooperates with a moving film to form a sound wave recordthereon or wherein the light beam passes from a movable film to form a sound wave record thereon or wherein the light beam passes from a movable film in the reproduction of sound from a sound wave record "previously formed on the latter. Slits of this character are ordinarily relatively long as compared with their width,'the width usually being small, asof the order of 0.1 to 0.05 mm., more or less. By my invention, the slit-forming device is of novel construction and is'constructed in a novel manner to thereby eliminate various disadvantages of prior art devlces.

Referring now to the form of my invention shown in Figs. 1, 2 and 3, A represents a plate or member of suitable sheet material having sections 1, 1a angularly related with respect to each other to-any suitable degree. The plate A may exist as a relatively straight piece of material and may be bent into suitable angular formation in any suitable manner. Or, an angular member of the character desired may be produced in any other suitable ably, the interior surfaces of the. angular sections 1 1a meet at a sharply defined single straight llne 2.

In accordance-with my invention a section of the member A at the nose or angleforming zone thereof is suitably removed,

as by .a grinding or milling o tin to" dlength;

produce a slit or passage 3 of a desi and of suitable width. As will bean-dammed, I I

the extent to which the material is thus re moved below the line 2 determines the itial width of the slit After a slit 3 of predetermined width has been produced as described above, the slit width may readily be increased or decreased by so movin the sections 1 and 1a thatthe angle forme thereby is either increased or decreased. If desired'but by no means necessarily, the slit width may be mechanically controlled by the provision of spaced screws 4 which extend loosely through the section 1a, For example, and are threaded to the section 1. Obviously, these screws 4 may be suitably adjusted to either increase or decrease the width of the slit 3 and, when so adjusted, said screws 4 function to positively prevent change in the slot width. it shall he understood that other equivalent arrangcments may be utilized in lieu of the screws 4 for performing the function just stated.

lVhere the width oi the slit is to he changed as described above, it may be desirable to utilize a. member A1 such as shown in Figs. 4. 5 and 6, the member Al being more or less identical with the member A with the exception that the nose or angular zone thereof is formed or constituted by tolded, sidc-by-side sections 5, 5a, Fig. 4. With such an arrangement, the surfaces limiting the slit are disposed well away from the joining section of the sections 1, la and, therefore, alteration of the slit width may be easily and eiiiciently efiected.

/Vith the form of my invention shown in Figs. 4, 5 and 6, it shall be understood that slit-controlling arrangen'ients such as the screws 4, or equivalent, may be utilized if desired.

In accordance witha preferred form of my invention the members A. A1, or equivalent, are one-piece sections of suitable sheet metal having sufiicient thickness as to be inherently self-supporting. it desired, such sheet metal may be relatively non-elastic whereby the angular sections thereof are in herently capable of taking and retaining a set configuration. Due to this characteristic, the angular sections readily remain in an adjusted position after adjustment thereof to obtain a desired slit width. If the sheet metal used is of a flexible and resilient nature, the device may be so formed that the angle between sections 1 and 1a is abnormally large, the screws as at 4 then being utilized to retain the sections 1 and 1a at the exact angle necessary to provide a slit of the desired width.'

As clearly appears from the drawing, the angular sections 1 and 1a remain joined together beyond opposite ends of the slit. In other words, the aforesaid material-removing operation maybe performed intermediate the ends of the members A and A1. This is an advantageous feature resulting in theproduction of a slit-forming device wherein the angular sections determining the slit width are integral with each other beyond the ends 0t the slit and, as a result, said slit width may readily be held constant or may be controlled in a desired manner/ The utilization of a one-piece member from which the slit-forming device is formed is advantageous aside from the features above emma pointed out. As regards those prior art arrangements wherein the slit is formed by the utilization of a plurality of plates, the one-piece device is a substantial in'lprovement in that when the device is to be used in an hermetically sealed chamber, the degasitying operation may more readily and more ellcient-ly he performed therewith. Further, with those prior art arrangements wherein a. straight metal plate is provided with a slit, the slit width is dependent upon the thickness of the tools which are employed, it being extremely ditticult to produce tools of the required degree of thinness and to obtain the desired slit after such tools have been produced. Obviously with the angular section employed in accordance with my invention, no such diiiiculty arises or is presented.

While the invention has been described with respect to certain particular preferred examples which give satisfactory results, it

will be understood by those skilledin the art after understanding the invention, that various changes and modifications may be made without departing from the spirit .and scope of the invention and it is intended therefore in the appended claims to cover all such changes and modifications.

What is claimed as new and desired to be secured by Letters Patent is:

1. A light aperture forming device comprising a member having sheet-like sections integral with each other and of sufiicient thickness to be inherently self-supporting, said sections meeting at an angle and defining a slit to be traversed by a light beam, said sections being joined together beyond the ends of said slit.

2. A light aperture forming device comprising a member having sheet-like sections integral with each other and of suflicientthickness to be inherently self-supporting, said sections meeting at an angle and defining a slit to be traversed by a light beam, said sections being oined together beyond the end of said slit-and being adjustable toward or from each other to vary the slit width.

3. A light aperture forming device comprising a member having sheet-like sections integral with each other and of suiiicient thickness to be inherently self-supporting, said sections meeting at an angle and defining a slit to be traversed by a light beam, and means for adjusting said sections relative to each other whereby the width of said slit may be changed.

4. A light aperture forming device comprising a molybdenum plate bent to form angularly related sections, the nose of said plate being cut away to form a slit extending lengthwise between said sections, said 'sections being adjustable toward or from each other to vary the width of said slit.

, 5. The method of producing a light aperture. slit-forming device, which comprises bending a. sheet metal plate into angular formation, and removing material from said member in its angle-forming 'zone to form an elongated slit therein.

6. The method'of producing a light aperture slit-forming device, which comprises a bending into angular formation a sheet metal plate inherently capable of retaining a set formation, and removing material fromsaid member in its angle-forming zone to form an elongated slit between the angular sections thereof.

7. A light aperture forming device comprising slit-forming members relatively movable angular-1y about a line along which said members meet for adjusting the width of the slit.

8. A light aperture forming device comprising a sheet of metal bent upon itself into contact centrally for a short distance and beyond extending divergingly, portions of the nose and the adjacent diverging sections be- 1 ing cut away to produce a slit to be traversed by a. light beam. i

In testimony whereof I have signed my name to this specification.

JOSEF ENGL. 

